The invention relates to a guide means for a gas turbine, in particular for an aircraft engine, to a gas turbine, in particular an aircraft engine having such a guide means, and to a method for assembly of such a guide means.
Such a guide means for a gas turbine is taken as being known from EP 2 554 794 A2. The guide means comprises at least one casing element as well as at least one first duct segment, which is arranged in the radial direction on the inside of the casing element. At least one duct, through which a gas can flow, is delimited at least partially outward in the radial direction by the first duct segment. The known guide means further comprises at least one second duct segment, which is arranged in the radial direction on the inside of the first duct segment and by means of which second duct segment, the duct is delimited at least partially inward in the radial direction. Moreover, the guide means comprises at least one guide vane, which is arranged at least partially in the duct and which can rotate around an axis of rotation relative to the casing element and relative to the duct segments. The duct is designed as an annular duct or annular space, for example, and serves to guide the gas, which can have a high temperature and accordingly can be a so-called hot gas. The guide vane serves to divert or redirect the gas flowing through the duct and can rotate around the axis of rotation between at least two positions that differ from one another. If, for example, a plurality of guide vanes are provided, which can move and, in particular, rotate relative to the casing element and to the duct segments and are arranged in succession in the circumferential direction, it is thereby possible to create a variable guide vane system or cascade of the gas turbine. The guide vanes and thus the gas turbine as a whole can be adapted as needed at different operating points by rotating the guide vanes, so that it is possible to realize an efficient operation of the gas turbine.
WO 2005/047656 A1 discloses a guide vane cascade for a turbomachine, in particular for a gas turbine, which has a plurality of fixed guide vanes positioned in an annular space or in a main flow duct. The guide vanes are designed so that each one is adjustable around a respective pivot axis, with the radial internal ends thereof bordering a first limiting surface of the annular space and the radial external ends thereof bordering a second limiting surface of the annular space. In this case, it is provided that the first limiting surface of the annular space and/or the second limiting surface of the annular space is embodied in such a manner that, in each pivotable position of the guide vanes, gaps are minimized between the radial internal ends of the guide vanes and the first limiting surface of the annular space and/or gaps are minimized between the radial external ends of the guide vanes and the second limiting surface of the annular space.
Furthermore, EP 0 757 161 A2 discloses a mounting assembly of a guide vane on a casing of a compressor of a gas turbine, wherein the guide vane is mounted on the casing via a bushing. In this case, the bushing is accommodated at least partially in a bore of the casing.